Hyperhidrosis is a disorder characterized by excessive sweating, namely sweating in excess of that required for the regulation of body temperature, that occurs in up to 1% of the population, with women being the predominant group affected by this condition. The excessive sweating associated with hyperhidrosis can occur in the hands (palmar hyperhidrosis), in the armpits (axillary hyperhidrosis), or in the feet (plantar hyperhidrosis). The underlying cause for primary hyperhidrosis, i.e., idiopathic hyperhidrosis, is not completely understood, but it is widely believed that an overactive sympathetic nervous system is involved, as it is known that sweating is generally under the control of the sympathetic nervous system. Secondary hyperhidrosis can be distinguished from primary hyperhidrosis as being due to a disorder of the thyroid or pituitary gland, diabetes mellitus, tumors, gout, menopause, or certain drugs.
Regardless of its causation, many patients afflicted with hyperhidrosis experience a distinct reduction in quality of life. Sufferers may feel a loss of control because perspiration can take place independent of temperature and sometimes emotional state. However, anxiety can frequently exacerbate the situation in many sufferers. Other factors are known to play a role; for example, certain foods and drinks, nicotine, caffeine, and smells can also trigger a response.
Hyperhidrosis can have a severe impact on quality of life and can interfere with the performance of routine activities. Perhaps one of the most severe consequences of hyperhidrosis is observed in work and social contexts. Patients with palmar hyperhidrosis have wet, moist hands that sometimes interfere with grasping objects. Many patients with palmar hyperhidrosis also consider it difficult to shake hands, as a handshake may leave the other person's palm very moist, a sensation most people find unpleasant. Those who suffer from axillary hyperhidrosis sweat profusely from their underarms causing them to stain their clothes shortly after they dress. These manifestations of hyperhidrosis place sufferers of this condition at a severe disadvantage in many social and professional situations.
In addition, the excessive sweating associated with hyperhidrosis impedes the performance of many routine activities. Activities such as driving, taking tests and simply grasping objects are severely hampered by sweaty hands. In addition, many careers and social situations present challenges for hyperhidrosis sufferers. For example, excessive sweating of the hands can be a debilitating condition because an individual's hands are much more exposed in social and professional activities than any other part of the body. Thus, many individuals with this condition may feel limited in their choice of professions and social interactions. For example, such individuals may be unable to manipulate materials sensitive to humidity (paper etc.) and are reluctant to shake hands. Other patients choose to minimize or avoid social contact.
A number of treatments are currently available for the treatment of hyperhidrosis; however, all of the treatments involve particular disadvantages for some patients.
A surgical procedure known as endoscopic thoracic sympathectomy or ETS is available in which selected sympathetic nerves or nerve ganglia in the chest are either cut or burned, thus completely destroying their ability to transmit impulses. Alternatively, these nerves can be clamped, thus affording the possibility of reversal of the procedure. However, this procedure often causes anhidrosis from the mid-chest upwards, which itself is a disturbing condition for many patients. Other major drawbacks to the procedure include thermoregulatory dysfunction (Goldstein, 2005), lowered fear and alertness (Teleranta, Pohjavaara, et at 2003, 2004) and the overwhelming incidence of compensatory hyperhidrosis. Many patients find the resultant compensatory hyperhidrosis to be worse than the initial condition. Moreover, the general risks normally associated with chest surgery are attendant with this procedure.
Another surgical treatment is sweat gland suction, which is a procedure modified from liposuction. Performed on an out-patient basis with only local anesthesia, the sweat glands are permanently removed. To perform this procedure, the sweat glands and armpits are first softened and anaesthetized with a special solution. After a short period, the sweat glands can then be removed by aspiration in a manner similar to liposuction.
Antiperspirants are another course of treatment for hyperhidrosis. The most effective antiperspirant agent appears to be 20 to 25% aluminum chloride in 70 to 90% alcohol, applied in the evening, 2 to 3 times/week. Aluminum chloride is the active agent found in a number of common antiperspirant products, including Drysol®, Maxim®, Odaban®, and Driclor®. However, hyperhidrosis sufferers generally need a much higher concentration than is found in ordinary commercially available products. Moreover, even a 15% or higher aluminum chloride solution usually takes about a week of nightly use to stop the sweating, with a follow-up of one or two nightly applications per week required to maintain the results. While aluminum chloride solutions can be effective, some people cannot tolerate the irritation that this agent causes in some users. Also, the solution is usually not effective for palmar (hand) and plantar (foot) hyperhidrosis.
Injections of the botulinum toxin (Botulinum toxin type A (trademarked as Botox®)) have also been used to disable the sweat glands. The effects can last from 4 to 9 months depending on the site of injections. For some patients, proper anesthesia may be required for the reduction of pain associated with injections to the hand and foot. Use of the procedure to treat underarm sweating has been approved by the FDA. However, this toxin is one of the most lethal poisons known, interfering with the effect of the neurotransmitter acetylcholine at synapses and potentially leading to progressive paralysis of all muscles in the body, including the respiratory muscles at higher doses than that used for treatment of hyperhidrosis. Another drawback is the cost of this treatment which has to be repeated at regular intervals.
Another method of treatment is iontophoresis which consists of the application of low intensity electric current (15-18 mA), supplied by a D/C generator, to the palms and/or soles immersed in an electrolyte solution. As the low current passes through an affected area, the minerals in the water clog the sweat glands, limiting the amount of sweat released. The procedure must be repeated regularly, initially in 20 minute sessions several times/week, with a gradual lengthening of the interval between treatments to 1 to 2 weeks. The results may vary; many patients, suffering from light or moderate hyperhidrosis, are satisfied with the method, while others may consider this procedure too time-consuming or inefficient, and comparably expensive. Moreover, this procedure is difficult to apply to the axillary area, and is not suitable for use in diffuse hyperhidrosis of the face or the trunk/thigh region. Also, this procedure has been found to be painful for some patients.
There are several drugs currently in use with varying degrees of success. A class of anticholinergic drugs has been shown to reduce hyperhidrosis. These drugs include Ditropan® (generic name: oxybutynin), which for some patients causes an unacceptable amount of drowsiness and dry-mouth; other less effective anticholinergic agents have also been used, including propantheline bromide (Probanthine®) and benztropine (Cogentin®). A different class of drugs which function as beta-blockers has also been tried, but these agents do not seem to be nearly as effective.
Glycopyrrolate is a quaternary amine of the muscarinic anticholinergic group. Glycopyrrolate has been used in the treatment of a variety of conditions including diarrhea (U.S. Pat. Nos. 6,214,792 and 5,919,760), urinary incontinence (U.S. Pat. Nos. 6,204,285 and 6,063,808), and anxiety (U.S. Pat. No. 5,525,347). Additionally, U.S. Pat. No. 5,976,499 discloses a method for diagnosing cystic fibrosis in a patient by, in part, stimulating sweat production through the injection of a glycopyrrolate solution into a patient.
Glycopyrrolate has also been previously used for the treatment of hyperhidrosis on an off-label basis, but as discussed below, these applications of glycopyrrolate lack the advantages of the present invention.
Abell et al., British Journal of dermatology 91: 87-91 (1974), discloses a method of treatment of hyperhidrosis including the use of glycopyrrolate in solutions for iontophoresis. A 0.5% aqueous solution of glycopyrrolate applied to the scalp and forehead for the treatment of hyperhidrosis has also been described in Seukeran et al., Clinical and Experimental Dermatology, 23: 204-205 (1998).
U.S. Pat. No. 6,433,003 to Bobrove discloses the topical use of about 0.25 to about 6% glycopyrrolate in the form of a lotion for the treatment of hyperhidrosis.
U.S. Pat. No. 7,060,289 to Wassenaar discloses a sealable container containing 30 rayon/polypropylene pads comprising 2% glycopyrrolate. This formulation of glycopyrrolate is not conducive to ease of use and ready portability, for instance, in a purse or briefcase or in an individual's pocket, as such a large container would be bulky and awkward to carry around on a routine basis. Furthermore, repeated opening of the sealable container of U.S. Pat. No. 7,060,289 would result, over time, in evaporation of the ethanol solution used in the glycopyrrolate formulation and a subsequent change in the concentration of the glycopyrrolate. Furthermore, continual exposure of the glycopyrrolate formulation of U.S. Pat. No. 7,060,289 to the air would also result, over time, in degradation of the active ingredient.
Given the drawbacks in terms of effectiveness and convenience of the presently available forms of treatment for hyperhidrosis, there remains a need for an effective, convenient, and easy to use formulation for the reduction of sweating caused in everyday situations that may exacerbate hyperhidrosis in sufferers of this condition.